Deposition of nanoporous silica films using a closed cup coater

ABSTRACT

A process for forming a uniform nanoporous dielectric film on a substrate. The process includes horizontally positioning a flat substrate within a cup; depositing a liquid alkoxysilane composition onto the substrate surface; covering the cup such that the substrate is enclosed therein; spinning the covered cup and spreading the alkoxysilane composition evenly on the substrate surface; exposing the alkoxysilane composition to water vapor and base vapor to thereby form a gel; and then curing the gel. The invention also provides an apparatus for spin depositing a liquid coating onto a substrate. The apparatus has a cylindrical cup with an open top section and removable cover which closes the top. A vapor injection port extends through the center of the cover. Suitable means hold a substrate centered within the cup and spin the cup.

CROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 60/095,573 file Aug. 6, 1998.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to the production integratedcircuits. More particularly, the invention relates to nanoporousdielectric coatings useful in the production of integrated circuits.

[0004] 2. Description of Prior Art

[0005] It is known in the art that, in the production of integratedcircuits, the problems of interconnect RC delay, power consumption andcrosstalk become more significant as feature sizes approach 0.25 μm andbelow. It has been found that the use of low dielectric constant (K)materials for interlevel dielectric and intermetal dielectricapplications partially mitigate these problems. However, each of thematerial candidates which are under consideration by the industry,having dielectric constants significantly lower than the currentlyemployed dense silica, suffer from disadvantages. Most low dielectricconstant materials developments use spin-on-glasses and fluorinatedplasma chemical vapor deposition of SiO₂ with K of >3. Some organic andinorganic polymers have dielectric constants in the range of about 2.2to 3.5, however, these polymers exhibit problems of low thermalstability, and poor mechanical properties including low glass transitiontemperature, and sample outgassing, thereby raising questions concerningtheir long term reliability questions.

[0006] Density, or its inverse, porosity, is the key parametercontrolling property of importance for dielectrics. Higher porositymaterials not only lead to a lower dielectric constant than densematerials, but they also allow additional components and processingsteps to be introduced. As density decreases, dielectric constant andmechanical strength decrease, however the pore size increases. Importantissues relating to porous materials include pore size; the strengthdecrease associated with porosity; and the role of surface chemistry ondielectric constant, loss and environmental stability.

[0007] One solution to these issues is the use of nanoporous silica,which can have dielectric constants in the range of about 1 to 3.Nanoporous silica is particularly attractive due to the ability tocarefully control its pore size and pore distribution, and because itemploys similar precursors such as tetraethoxysilane (TEOS), as ispresently used for spin-on glass (SOG's), and CVD SiO₂. In addition tohaving low dielectric constants, nanoporous silica offers otheradvantages for microelectronics, including thermal stability up to 900°C.; small pore size (<< microelectronics features); use of materials,namely silica and its precursors, that are widely used in thesemiconductor industry; the ability to tune dielectric constant over awide range; and deposition using similar tools as employed forconventional spin-on glass processing. EP patent application EP 0 775669 A2, which is incorporated herein by reference, shows a method forproducing a nanoporous silica film with uniform density throughout thefilm thickness.

[0008] Nanoporous silica films are typically fabricated by methods suchas dip-coating or spin-coating. When spin-coating, a mixture of asolvent and a silica precursor is deposited on a substrate wafer whichis placed on a chuck in an open cup. The substrate is spun at severalthousand rotations per minute (rpm's) in order to achieve a uniformlythin film on the substrate. Typically, the substrate is open to theatmosphere such that excess fluid can be flung from the substrate edge.However, turbulence around the substrate often results in a film whichis not completely uniform, and which may vary in thickness. Turbulenceis believed to cause defects such as striations, which are thicknessgradients in the deposited film that are started at the center of thesubstrate and spiral radially outward to the edge of the substrate. Thiscan cause a film to be non-uniform.

[0009] The present invention offers a solution to these problems. It hasbeen unexpectedly found that using a closed cup when spin-coating willreduce turbulence around the substrate and result in a more uniformfilm. According to the present invention, a cover is placed over thesubstrate wafer so that the cup, cover, and substrate spinsimultaneously. This simultaneous spinning eliminates turbulence that isnormally found in traditional spin coating processes where only thesubstrate spins and the cup is stationary. Subsequently, vapors of waterand a base such as ammonia are injected into the cover of the cup.Because of the lower turbulence due to the covering of the cup, thesilica precursor is uniformly exposed to the vapors and is polymerizeduntil it forms a gel. After this exposure, the substrate is ready forcuring. Using this approach, a nanoporous silica film-is obtained withuniform density and film thickness. In another embodiment of theinvention, the precursor can be reacted with the base and water vaporafter removal from the cup.

SUMMARY OF THE INVENTION

[0010] This invention provides a process for forming a nanoporousdielectric coating on a substrate which comprises:

[0011] a) horizontally positioning a flat substrate within a cup;

[0012] b) depositing a liquid alkoxysilane composition onto a surface ofthe substrate;

[0013] c) covering the cup such that the substrate is enclosed therein;

[0014] d) spinning the covered cup and spreading the alkoxysilanecomposition evenly on the substrate surface;

[0015] e) exposing the alkoxysilane composition to sufficient watervapor, base vapor or both water vapor and base vapor to thereby form agel; and

[0016] f) curing the gel.

[0017] This invention further provides a semiconductor device producedby a process which comprises:

[0018] a) horizontally positioning a flat semiconductor substrate withina cup;

[0019] b) depositing a liquid alkoxysilane composition onto a surface ofthe substrate;

[0020] c) covering the cup such that the substrate is enclosed therein;

[0021] d) spinning the covered cup and spreading the alkoxysilanecomposition evenly on the substrate surface;

[0022] e) exposing the alkoxysilane composition to sufficient watervapor, base vapor or both water vapor and base vapor to thereby form agel; and

[0023] f) curing the gel.

[0024] This invention still further provides an apparatus for spindepositing a liquid coating onto a substrate which comprises:

[0025] a) a cylindrical cup having an open top section;

[0026] b) a removable cover which engages with and closes the topsection;

[0027] c) a vapor injection port extending through the center of thecover;

[0028] d) means for holding a substrate centered within the cup; and

[0029] e) means for spinning the cup.

BRIEF DESCRIPTION OF THE DRAWINGS

[0030]FIG. 1 shows a schematic representation of a closed rotary cupuseful for the invention.

[0031]FIG. 2 shows schematic representations of an alternate embodimentof a closed rotary cup useful for the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0032] In the practice of the present invention, an alkoxysilaneprecursor composition is formed from at least one alkoxysilane and asolvent composition. A substrate wafer, optionally having a pattern ofraised lines on its surface (as described below), is horizontally placedinside a coverable cup. Then the alkoxysilane precursor composition isapplied onto the substrate. The cup is covered and spun to relativelyuniformly apply a layer of the precursor composition onto the substrate.The precursor composition is then exposed to water vapor and base vapor.In one embodiment of the present invention, the water and base vapor areinjected directly into the closed cup. In another embodiment, the coatedsubstrate is exposed to the water and base vapor after the substrate isremoved from the cup. Exposure to these vapors hydrolyzes and condensesthe precursor composition until it forms a gel layer which issubsequently cured to form a nanoporous dielectric film on the surfaceof the substrate.

[0033] Useful alkoxysilanes for this invention include those which havethe formula:

[0034] wherein at least 2 of the R groups are independently C₁ to C₄alkoxy groups and the balance, if any, are independently selected fromthe group consisting of hydrogen, alkyl, phenyl, halogen, andsubstituted phenyl. For purposes of this invention, the term alkoxyincludes any other organic group which can be readily cleaved fromsilicon at temperatures near room temperature by hydrolysis. R groupscan be ethylene glycoxy or propylene glycoxy or the like, but preferablyall four R groups are methoxy, ethoxy, propoxy or butoxy. The mostpreferred alkoxysilanes nonexclusively include tetraethoxysilane (TEOS)and tetramethoxysilane.

[0035] Preferably, the solvent composition comprises a relatively highvolatility solvent or a relatively low volatility solvent or both arelatively high volatility solvent and a relatively low volatilitysolvent. The solvent, usually the higher volatility solvent, is at leastpartially evaporated immediately after deposition onto the substrate.This partial drying leads to better planarity due to the spinning of alower viscosity material after the first solvent or parts of the solventcomes off. The more volatile solvent evaporates over a period of secondsor minutes. Slightly elevated temperatures may optionally be employed toaccelerate this step. Such temperatures preferably range from about 20°C. to about 80° C., more preferably from about 20° C. to about 50° C.and most preferably from about 20° C. to about 35° C.

[0036] For purposes of this invention, a relatively high volatilitysolvent is one which evaporates at a temperature below, preferablysignificantly below, that of the relatively low volatility solvent. Therelatively high volatility solvent preferably has a boiling point ofabout 120° C. or less, more preferably about 100° C. or less. Suitablehigh volatility solvents nonexclusively include methanol, ethanol,n-propanol, isopropanol, n-butanol and mixtures thereof. Otherrelatively high volatility solvent compositions which are compatiblewith the other ingredients can be readily determined by those skilled inthe art.

[0037] The relatively low volatility solvent composition is one whichevaporates at a temperature above, preferably significantly above, thatof the relatively high volatility solvent. The relatively low volatilitysolvent composition preferably has a boiling point of about 175° C. orhigher, more preferably about 200° C. or higher. Suitable low volatilitysolvent compositions nonexclusively include alcohols and polyolsincluding glycols such as ethylene glycol, 1,4-butylene glycol,1,5-pentanediol, 1,2,4-butanetriol, 1,2,3-butanetriol,2-methyl-propanetriol, 2-(hydroxymethyl)-1,3-propanediol,1,4,1,4-butanediol, 2-methyl-1,3-propanediol, tetraethylene glycol,triethylene glycol monomethyl ether, glycerol and mixtures thereof.Other relatively low volatility solvent compositions which arecompatible with the other ingredients can be readily determined by thoseskilled in the art.

[0038] The alkoxysilane component is preferably present in an amount offrom about 3% to about 50% by weight of the overall blend, morepreferably from about 5% to about 45% and most preferably from about 10%to about 40%.

[0039] The solvent component is preferably present in an amount of fromabout 20% to about 90% by weight of the overall blend, more preferablyfrom about 30% to about 70% and most preferably from about 40% to about60%. When both a high and a low volatility solvent are present, the highvolatility solvent component is preferably present in an amount of fromabout 20% to about 90% by weight of the overall blend, more preferablyfrom about 30% to about 70% and a most preferably from about 40% toabout 60% by weight of the overall blend. When both a high and a lowvolatility solvent are present, the low volatility solvent component ispreferably present in an amount of from about 1 to about 40% by weightof the overall blend, more preferably from about 3% to about 30% and amost preferably from about 5% to about 20% by weight of the overallblend.

[0040] Typical substrates are those suitable to be processed into anintegrated circuit or other microelectronic device. Suitable substratesfor the present invention non-exclusively include semiconductormaterials such as gallium arsenide (GaAs), silicon and compositionscontaining silicon such as crystalline silicon, polysilicon, amorphoussilicon, epitaxial silicon, and silicon dioxide (SiO₂) and mixturesthereof. Lines may optionally be on the substrate surface. The lines,when present, are typically formed by well known lithographic techniquesand may be composed of a metal, an oxide, a nitride or an oxynitride.Suitable materials for the lines include silica, silicon nitride,titanium nitride, tantalum nitride, aluminum, aluminum alloys, copper,copper alloys, tantalum, tungsten and silicon oxynitride. These linesform the conductors or insulators of an integrated circuit. Such aretypically closely separated from one another at distances preferably offrom about 20 micrometers or less, more preferably from about 1micrometer or less, and most preferably of from about 0.05 to about 1micrometer.

[0041] According to the invention, the alkoxysilane precursorcomposition is applied to the substrate surface and spun inside a closedcup. As can be seen in FIG. 1, a typical cup 5 is provided with aremovable cover 2. Inside the cup 5, a substrate wafer 4 rests on aplatform 10 which retains the substrate centered within the cup. The cupis connected to a rotor stem 8. The rotor stem 8 is then attached to amotor (not shown). In the practice of the present invention, a motor(not shown) rotates rotor stem 8. This rotation causes the cup 5, cover2, and substrate 4 to spin, evenly distributing the silane precursor onthe substrate 4. Another key feature of the design is the very smallvoid space 3 (<5 mm) above the substrate 4 and below the cover 2. Thisvoid space minimizes the solvent evaporation during spin deposition toallow for a controlled solvent environment. This covered rotary cupdesign is preferably used to cause gelation of nanoporous silica filmsby injecting the water and base vapors before, during, or after spindeposition. Because of the lower turbulence, the film surface isuniformly exposed to the water vapor/ base catalyst but because of thehigh substrate velocities, high mass transfer rates to the liquidprecursor are achieved resulting in short reaction times. Therefore,directly after deposition and water/catalyst exposure, the substrate maybe removed from the closed cup and processed through a conventional hotplate bake and cure procedure.

[0042]FIG. 2 shows another embodiment of the present invention. In FIG.2, the cover 2 of cup 5 further comprises a vapor injection port whichmay comprise a tube 12 and a coupling 14 which are used to inject watervapor and/or base vapor into the cup. The injection port is mounted tothe cover 2 via a coupling 14. In one embodiment, the tube 12 isremovable from the coupling 14 and the injection port is sealed prior tospinning the substrate in the closed cup. In another embodiment, thetube and coupling are rotatably mounted to the cover 2 so that the tubeand coupling remain stationary while the cup 5 and cover 2 are spun.This can be achieved by a variety of means such as mounting the coupling14 to a track within the cover 2 of the cup in a tongue-in-groovearrangement. Suitable materials for the apparatus of the presentinvention nonexclusively include stainless steel, plastic, and the like.Stainless steel cups can be purchased from SEMIX, Inc. of Fremont,Calif., or from TEL America of Austin, Tex. Such may then be providedwith the above described coupling arrangement.

[0043] As stated above, the coating is exposed to both a water vapor anda base vapor in the cup. The water vapor causes a continued hydrolysisof the alkoxysilane alkoxy groups, and the base catalyzes condensationof the hydrolyzed alkoxysilane and serves to increase molecular weightuntil the coating gels, and ultimately increases gel strength.Preferably, the coating is first exposed to a water vapor and thenexposed to a base vapor, however, in an alternate embodiment, thecoating may first be exposed to a base vapor and then a water vapor. Forpurposes of this invention, a base vapor includes gaseous bases.

[0044] The base is present in a catalytic amount which can be readilydetermined by those skilled in the art. Preferably the molar ratio ofbase to silane ranges from about 0 to about 0.2, more preferably fromabout 0.001 to about 0.05, and most preferably from about 0.005 to about0.02. Water is included to provide a medium for hydrolyzing thealkoxysilane. The mole ratio of water to silane is preferably from about0 to about 50, more preferably from about 0.1 to about 10 and a mostpreferably from about 0.5 to about 1.5.

[0045] In the preferred embodiment, the mole ratio of water vapor tobase vapor preferably ranges from about 1:3 to about 1:100, morepreferably from about 1:5 to about 1:50, and most preferably from about1:10 to about 1:30.

[0046] In the preferred embodiment, the temperature of the water duringthe exposure. preferably ranges from about 10° C. to about 60° C., morepreferably from about 15° C. to about 50° C., and most preferably fromabout 20° C. to about 40° C. In the preferred embodiment, thetemperature in the chamber after water exposure preferably ranges fromabout 10° C. to about 50° C., more preferably from about 15° C. to about40° C., and most preferably from about 20° C. to about 40° C.

[0047] In the preferred embodiment, the temperature of the base duringthe exposure preferably ranges from about 10° C. to about 60° C., morepreferably from about 15° C. to about 40° C., and most preferably fromabout 20° C. to about 30° C. In the preferred embodiment, thetemperature after base exposure preferably ranges from about 10° C. toabout 50° C., more preferably from about 15° C. to about 40° C., andmost preferably from about 20° C. to about 40° C.

[0048] Suitable bases for use in the base vapor nonexclusively includeammonia and amines, such as primary, secondary and tertiary alkylamines, aryl amines, alcohol amines and mixtures thereof which have apreferred boiling point of about 200° C. or less, more preferably 100°C. or less and most preferably 25° C. or less. Preferred amines aremethylamine, dimethylamine, trimethylamine, n-butylamine, n-propylamine,tetramethyl ammonium hydroxide, piperidine and 2-methoxyethylamine. Theability of an amine to accept a proton in water is measured in terms ofthe basicity constant K_(b), and pK_(b)=−log K_(b). In the preferredembodiment, the pK_(b) of the base may range from about less than 0 toabout 9, more preferably from about 2 to about 6 and most preferablyfrom about 4 to about 5.

[0049] Once it forms into a gel, the film may be cured or dried in aconventional way by solvent evaporation of the less volatile solvent.Elevated temperatures may be employed to dry the coating in this step.Such temperatures preferably range from about 20° C. to about 450° C.,more preferably from about 50° C. to about 350° C. and most preferablyfrom about 175° C. to about 320° C.

[0050] As a result, a relatively high porosity, low dielectric constant,silicon containing polymer composition forms on the substrate. Thesilicon containing polymer composition preferably has a dielectricconstant of from about 1.1 to about 3.5, more preferably from about 1.3to about 3.0, and most preferably from about 1.5 to about 2.5. The poresize of silica composition preferably ranges from about 1 nm to about100 nm, more preferably from about 2 nm to about 30 nm, and mostpreferably from about 3 nm to about 20 nm. The density of the siliconcontaining composition, including the pores, preferably ranges fromabout 0.1 to about 1.9 g/cm², more preferably from about 0.25 to about1.6 g/cm², and most preferably from about 0.4 to about 1.2 g/cm².

[0051] The following nonlimiting examples serve to illustrate theinvention.

EXAMPLE 1

[0052] This example demonstrates that the use of a rotary cup for spincoating can eliminate/minimize film non-uniformity's (i.e. radialstriations).

[0053] The precursor is synthesized by adding 104.0 mL oftetraethoxysilane, 47.0 mL of triethylene glycol monomethyl ether, 8.4mL of deionized water, and 0.34 mL of 1N nitric acid together in a roundbottom flask. The solution is allowed to mix vigorously, and is thenheated to ˜80° C. and refluxed for 1.5 hours to form a solution. Afterthe solution is allowed to cool, it is diluted 25% by weight withethanol to reduce the viscosity. The diluted precursor is filtered to0.1 μm using a teflon filter.

[0054] Two nanoporous silica films are processed in which the first isdeposited using a rotary closed cup spin coater while the other is spunon a conventional coater. The first substrate wafer is spun on a rotarycup coater using the following process sequence: Open the cup and placesubstrate on a chuck. Deposit 2.0-10.0 ml of precursor and close thecup. Spin substrate and cup simultaneously to minimize the turbulence.Open the cup and spin at low rpm (<50 rpm) to allow for solventevaporation. Continue processing the substrate. The second film isdeposited on a conventional spin coater using the following processsequence. Place the substrate on the chuck. Deposit 2.0-10.0 ml of theprecursor and spin at 2500 rpm for 30 seconds. Continue processingsubstrate.

[0055] The films are gelled and aged in a vacuum chamber using thefollowing conditions. The chamber is evacuated to −20 inches of Hg.Next, 15M ammonium hydroxide is heated and equilibrated at 45° C. anddosed into the chamber to increase the pressure to −4.0 inches of Hg for2-3 minutes. Finally, the chamber is evacuated to −20.0 inches of Hg andbackfilled with nitrogen. The films are then solvent exchanged by which25-50 mL of a 50/50 (by vol.) mixture of 3-pentanone andhexamethyldisilazane (Pacific Pac, Hollister, Calif. 95023) are spun onthe film at 250 rpm's for 20 seconds without allowing the film to dry.The films are then spun dry at 1000 rpm for 5 seconds. The films areheated at elevated temperatures for 1 min. each at 175° C. and 320° C.in air. The films are characterized by ellipsometry to determine therefractive indices and thicknesses. In addition, the films are inspectedusing a light microscope at a magnification of 400× to observe forradial striations. The rotary closed cup processed film has no observedstriations and has excellent thickness and refractive index uniformitywhile the regular deposited film shows some striations and poorerrelative surface uniformity.

EXAMPLE 2

[0056] This example demonstrates that the use of a rotary cup for spincoating can improve global planarity on patterned substrates.

[0057] A precursor is synthesized by adding 104.0 mL oftetraethoxysilane, 47.0 mL of triethylene glycol monomethyl ether, 8.4mL of deionized water, and 0.34 mL of 1N nitric acid together in a roundbottom flask. The solution is allowed to mix vigorously, and is thenheated to ˜80° C. and refluxed for 1.5 hours to form a solution. Afterthe solution is allowed to cool, it is diluted 25% by weight withethanol to reduce the viscosity. The diluted precursor is filtered to0.1 μm using a teflon filter.

[0058] Two nanoporous silica films are processed in which the first isdeposited using a rotary cup spin coater while the other is spun on aconventional coater. The first substrate is spun on a rotary closed cupcoater using the following process sequence. Open the cup and place thepatterned substrate on the chuck. Deposit 2.0-10.0 ml of precursor usinga static dispense and close the cup. Spin the film at 2-3 krpm for30-180 seconds. Planarize the precursor by spinning at a very high rpm(˜5 krpm). Open the cup and spin dry the substrate at a low rpm (<50rpm) to allow for solvent evaporation. Continue processing thesubstrate. The second film is deposited on a conventional spin coaterusing the following process sequence: Place the patterned substrate onthe chuck. Deposit 2.0-10.0 ml of the precursor and spin at 2500 rpm for30 seconds. Continue processing substrate. The films are gelled and agedin a vacuum chamber using the following conditions. The chamber isevacuated to −20 inches of Hg. Next, 15M ammonium hydroxide is heatedand equilibrated at 45° C. and dosed into the chamber to increase thepressure to −4.0 inches Hg for 2-3 minutes. Finally, the chamber isevacuated to −20.0 inches of Hg and backfilled with nitrogen.

[0059] The films are then solvent exchanged by which 25-50 mL of a 50/50(by vol.) mixture of 3-pentanone and hexamethyldisilazane are spun onthe film at 250 rpm's for 20 seconds without allowing the film to dry.The films are then spun dry at 1000 rpm for 5 seconds.

[0060] The films are heated at elevated temperatures for 1 min. each at175° C. and 320° C. in air. The films are inspected by cross-sectionalSEM at a magnification of 5000-40000× to observe for global planarity.It is observed that the rotary closed cup film has relatively betterglobal planarity while the regularly deposited film shows relativelypoorer global planarity.

EXAMPLE 3

[0061] Example 1 is repeated except after precursor deposition, it isgelled and aged by first dosing water vapor into the closed cup.Thereafter, ammonium hydroxide vapor is dosed into the closed cup.

EXAMPLE 4

[0062] Example 1 is repeated except after precursor deposition, it isgelled and aged by first dosing ammonium hydroxide vapor into the closedcup. Thereafter, water vapor is dosed into the closed cup.

EXAMPLE 5

[0063] Example 1 is repeated except after precursor deposition, it isgelled and aged by dosing a mixture of water and ammonium hydroxidevapor into the closed cup.

[0064] The foregoing examples show that by using closed cup spin coatingof a substrate with a nanoporous coating composition precursor, thatfilms having improved planarity and striation characteristics areproduced.

What is claimed is:
 1. A process for forming a nanoporous dielectriccoating on a substrate which comprises: a) horizontally positioning aflat substrate within a cup; b) depositing a liquid alkoxysilanecomposition onto a surface of the substrate; c) covering the cup suchthat the substrate is enclosed therein; d) spinning the covered cup andspreading the alkoxysilane composition evenly on the substrate surface;e) exposing the alkoxysilane composition to sufficient water vapor, basevapor or both water vapor and base vapor to thereby form a gel; and f)curing the gel.
 2. The coated substrate produced according to claim 1.3. A semiconductor device produced by a process which comprises: a)horizontally positioning a flat semiconductor substrate within a cup; b)depositing a liquid alkoxysilane composition onto a surface of thesubstrate; c) covering the cup such that the substrate is enclosedtherein; d) spinning the covered cup and spreading the alkoxysilanecomposition evenly on the substrate surface; e) exposing thealkoxysilane composition to sufficient water vapor, base vapor or bothwater vapor and base vapor to thereby form a gel; and f) curing the gel.4. An apparatus for spin depositing a liquid coating onto a substratewhich comprises: a) a cylindrical cup having an open top section; b) aremovable cover which engages with and closes the top section; c) avapor injection port extending through the center of the cover; d) meansfor holding a substrate centered within the cup; and e) means forspinning the cup.
 5. The cup of claim 4 wherein the vapor injection portcomprises a coupling mounted with the cover, and a tube mounted to thecoupling; which coupling is rotatably mounted to the cover such that thetube and coupling remain substantially stationary when the cover and cupare caused to spin.